Once, looking down in the direction of the bridge, I gave a great start, for a black patch of shadow moved swiftly across the path and merged into the other shadows bordering a high wall. My heart leapt momentarily, then, in another instant, the explanation of the mystery became apparent--in the presence of a gaunt and prowling cat. Bestowing a suspicious glance upward in my direction, the animal slunk away toward the path bordering the cutting. By a devious route amid ghostly gasometers I had crept to my post in the early dusk, before the moon was risen, and already I was heartily weary of my passive part in the affair of the night. I had never before appreciated the multitudinous sounds, all of them weird and many of them horrible, which are within the compass of those great black rats who find their way to England with cargoes from Russia and elsewhere. From the rafters above my head, from the wall recesses about me, from the floor beneath my feet, proceeded a continuous and nerve-shattering concert, an unholy symphony which seemingly accompanied the eternal dance of the rats. Sometimes a faint splash from below would tell of one of the revelers taking the water, but save for the more distant throbbing of riverside industry, and rarer note of shipping, the mad discords of this rat saturnalia alone claimed the ear. The hour was nigh now, when matters should begin to develop. I followed the chimes from the clock of some church nearby--I have never learnt its name; and was conscious of a thrill of excitement when they warned me that the hour was actually arrived.... A strange figure appeared noiselessly, from I knew not where, and stood fully within view upon the bridge crossing the cutting, peering to right and left, in an attitude of listening. It was the figure of a bedraggled old woman, gray-haired, and carrying a large bundle tied up in what appeared to be a red shawl. Of her face I could see little, since it was shaded by the brim of her black bonnet, but she rested her bundle upon the low wall of the bridge, and to my intense surprise, sat down upon it! She evidently intended to remain there. I drew back further into the darkness; for the presence of this singular old woman at such a place, and at that hour, could not well be accidental. I was convinced that the first actor in the drama had already taken the stage. Whether I was mistaken or not must shortly appear. Crisp footsteps sounded upon the roadway; distantly, and from my left. Nearer they approached and nearer. I saw the old woman, in the shadow of the wall, glance once rapidly in the direction of the approaching pedestrian. For some occult reason, the chorus of the rats was stilled. Only that firm and regular tread broke the intimate silence of the dreary spot. Now the pedestrian came within my range of sight. It was Nayland Smith!